The present disclosure relates to ammunition and more particularly to training ammunition.
The United States Army uses 40 mm grenade machine guns within the tactical environment for defense, retrograde, patrolling, rear area security, urban operations, and special operations. These weapon systems are deployed in all environments, e.g., during the day and also limited visibility conditions, such as night, fog, and other obscurant conditions. The need for improvements in night fighting capabilities and the fielding of thermal weapon sights technology have lead to a training gap. There is also a need for a training capability which enables the war fighter to be able to “train as you fight.” The current target practice cartridge provides an impact signature. However, it is limited in range to about 1299 meters during the day and 500 meters at night. Additionally the current target practice cartridge does not provide a thermal or infrared signature.
One conventional target practice cartridge, the M918 round, is shown in cross section in FIG. 1. This 40 mm cartridge 10 includes a M169 metal cartridge case 11 and a “flash/bang” projectile assembly 17. The case 11 has a base plug 12 which holds a percussion primer 14 in place adjacent a propellant charge 15 in a closing cup portion 16 of the case 11. The flash/bang projectile assembly 17 includes a projectile body assembly (steel body with copper rotating band swaged for retention thereon) forming a container 18 and an ogive 19 fastened onto the container 18. This container holds a capsule assembly 20 that holds a flash charge composition 21. Within the ogive 19 is a firing pin assembly 22, an anti creep spring 23, and a fuze escapement assembly 24 which, upon target impact, ignites the flash charge composition 21.
Around the outside of the projectile container 18 is a ring or band of material called the rotating band 25. This rotating band 25 engages lands and grooves in the bore of the barrel of the weapon to rotate the projectile 17 as it travels through the bore providing flight stability to the projectile 17 as it thereafter flies down range.
The M918 40 mm training round provides an impact signature out to beyond approximately 1000 meters. However, should the projectile 17 land in soft earth, the firing pin assembly malfunction, or the fuze assembly malfunction, it detrimentally also can produce an unexploded ordnance hazard. This is highly undesirable. Thus there is a need in military training regimens for use of training ammunition that does not involve energetic payloads, thus eliminating energetic unexploded ordnance risk.